Computer and communication technologies continue to advance at a rapid pace. Indeed, computer and communication technologies are involved in many aspects of a person's day. For example, many devices being used today by consumers have a small computer inside of the device. These small computers come in varying sizes and degrees of sophistication. These small computers include everything from one microcontroller to a fully-functional complete computer system. For example, these small computers may be a one-chip computer, such as a microcontroller, a one-board type of computer, such as a controller, a typical desktop computer, such as an IBM-PC compatible, etc.
Computers typically have one or more processors at the heart of the computer. The processor(s) usually are interconnected to different external inputs and outputs and function to manage the particular computer or device. For example, a processor in a thermostat may be connected to buttons used to select the temperature setting, to the furnace or air conditioner to change the temperature, and to temperature sensors to read and display the current temperature on a display.
Many appliances, devices, etc., include one or more small computers. For example, thermostats, furnaces, air conditioning systems, refrigerators, telephones, typewriters, automobiles, vending machines, and many different types of industrial equipment now typically have small computers, or processors, inside of them. Computer software runs the processors of these computers and instructs the processors how to carry out certain tasks. For example, the computer software running on a thermostat may cause an air conditioner to stop running when a particular temperature is reached or may cause a heater to turn on when needed.
These types of small computers that are a part of a device, appliance, tool, etc., are often referred to as embedded devices or embedded systems. (The terms “embedded device” and “embedded system” will be used interchangeably herein.) An embedded system usually refers to computer hardware and software that is part of a larger system. Embedded systems may not have typical input and output devices such as a keyboard, mouse, and/or monitor. Usually, at the heart of each embedded system is one or more processor(s).
A lighting system may incorporate an embedded system. The embedded system may be used to monitor and control the effects of the lighting system. For example, the embedded system may provide controls to dim the brightness of the lights within the lighting system. Alternatively, the embedded system may provide controls to increase the brightness of the lights. The embedded system may provide controls to initiate a specific lighting pattern among the individual lights within the lighting system. Embedded systems may be coupled to individual switches within the lighting system. These embedded systems may instruct the switches to power up or power down individual lights or the entire lighting system. Similarly, embedded systems may be coupled to individual lights within the lighting system. The brightness or power state of each individual light may be controlled by the embedded system.
A security system may also incorporate an embedded system. The embedded system may be used to control the individual security sensors that comprise the security system. For example, the embedded system may provide controls to power up each of the security sensors automatically. Embedded systems may be coupled to each of the individual security sensors. For example, an embedded system may be coupled to a motion sensor. The embedded system may power up the individual motion sensor automatically and provide controls to activate the motion sensor if motion is detected. Activating a motion sensor may include providing instructions to power up an LED located within the motion sensor, output an alarm from the output ports of the motion sensor, and the like. Embedded systems may also be coupled to sensors monitoring a door. The embedded system may provide instructions to the sensor monitoring the door to activate when the door is opened or closed. Similarly, embedded systems may be coupled to sensors monitoring a window. The embedded system may provide instructions to activate the sensor monitoring the window if the window is opened or closed.
Some embedded systems may also be used to control wireless products such as cell phones. The embedded system may provide instructions to power up the LED display of the cell phone. The embedded system may also activate the audio speakers within the cell phone to provide the user with an audio notification relating to the cell phone.
Home appliances may also incorporate an embedded system. Home appliances may include appliances typically used in a conventional kitchen, e.g., stove, refrigerator, microwave, etc. Home appliances may also include appliances that relate to the health and well-being of the user. For example, a massage recliner may incorporate an embedded system. The embedded system may provide instructions to automatically recline the back portion of the chair according to the preferences of the user. The embedded system may also provide instructions to initiate the oscillating components within the chair that cause vibrations within the recliner according to the preferences of the user.
Additional products typically found in homes may also incorporate embedded systems. For example, an embedded system may be used within a toilet to control the level of water used to refill the container tank. Embedded systems may be used within a jetted bathtub to control the outflow of air.
As stated, embedded systems may be used to monitor or control many different systems, resources, products, etc. With the growth of the Internet and the World Wide Web, embedded systems are increasingly connected to the Internet so that they can be remotely monitored and/or controlled. Other embedded systems may be connected to computer networks including local area networks, wide area networks, etc. As used herein, the term “computer network” (or simply “network”) refers to any system in which a series of nodes are interconnected by a communications path. The term “node” refers to any device that may be connected as part of a computer network. An embedded system may be a network node. Other examples of network nodes include computers, personal digital assistants (PDAs), cell phones, etc.
Some embedded systems may provide data and/or services to other computing devices using a computer network. Many different kinds of services may be provided. Some examples of services include providing temperature data from a location, providing surveillance data, providing weather information, providing an audio stream, providing a video stream, etc. As used herein, the term “requester” refers to a node that requests a service from a provider. The term “provider” refers to a node that provides a service to a requestor.
Some of the nodes within a computer network may be configured to send messages to other nodes on the network using multicast technology. Within the context of computer networks, the term “multicasting” refers to the process of sending a message simultaneously to more than one node on the network. Multicasting is different from broadcasting in that multicasting means sending a message to specific groups of nodes within a network, whereas broadcasting implies sending a message to all of the nodes on the network.
A node that is requesting a service (i.e., a requester) may send a service request to other nodes within the network via multicast. However, several issues have arisen with known approaches to the use of multicast technology on a computer network to request services. For example, a computer network may include one or more resource-constrained nodes that are not capable of receiving and/or processing multicast messages. If a requestor sends a request for a service to other nodes within the network via multicast, these resource-constrained nodes may not receive (and therefore have an opportunity to respond to) the service request.
Another issue with known approaches is that each node that receives a service request via multicast typically determines whether it provides the requested service, and if it does, it responds to the service request. Such an approach may be inefficient under some circumstances because several nodes that do not provide the requested service may still process a request for the service.
Yet another issue with known approaches is that it may be discovered that one or more nodes within the network are defective in some way. If this occurs, it may be desirable to prevent such nodes from directly processing multicast messages. This may be accomplished by shutting down the appropriate multicast protocol stack on the node. However, such an approach may not be desirable under some circumstances because this may prevent such nodes from receiving and responding to service requests that are sent on the network via multicast.
In view of the foregoing, benefits may be realized by improvements related to the use of multicast technology on a computer network. Accordingly, some exemplary systems and methods for facilitating more efficient processing of multicast requests on a computer network are disclosed herein.